/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/ContactModification.h
The contact normal always points away from the second body. E.g., a sphere lying on a flat ground could return a WorldNormal pointing up or down, depending on whether the sphere is the first or second body in the constraint.
Normal of contact in world space.
[FVec3](API\Runtime\ChaosCore\Chaos\FVec3) GetWorldNormal ( int32 ContactPointIdx ) const